/usr/lib/plainbox-providers-1/checkbox/bin/gcov_tarball is in plainbox-provider-checkbox 0.3-2.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | #!/bin/sh
set -o errexit
cd /usr/share
tar -xzf gcov.tar.gz
cd /tmp
lcov -q -c -o gcov.info
genhtml -q -o gcov gcov.info 2>/dev/null
tar -czf - gcov
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